guardian vs valet-de-chambre

guardian

noun
  • A superior in a Franciscan monastery. 

  • A person legally responsible for a minor (in loco parentis). 

  • A person legally responsible for an incompetent person. 

  • Someone who guards, watches over, or protects. 

  • A major or final enemy; boss. 

valet-de-chambre

noun
  • The personal servant of a monarch. 

  • A valet. 

How often have the words guardian and valet-de-chambre occurred in a corpus of books? (source: Google Ngram Viewer )